Many diverse therapeutic indications exist in which augmenting the flow of fluid within a body vessel is required or at least clinically beneficial. Inadequate blood and fluid flow in regions of the body can lead to pain, tissue swelling, edema, prolonged wound healing time, and forms of stasis, such as leg swelling; stasis dermatitis; stasis ulcers; arterial and diabetic skin ulcers; and other conditions of skin irritation and breakdown (ulcer) due to the accumulation of fluid under the skin resulting from poor blood and fluid circulation. Fluid leaks from the veins into skin tissue when blood backs up rather than returning to the heart through the veins.
Deep Vein Thrombus (DVT) is another example in which augmenting the flow of fluid within a body vessel is clinically important. DVT is the formation of a blood clot in a deep vein. Blood clots (thrombus) form in regions of slow moving or disturbed blood flow, usually in the large veins of the legs, leading to partial or completely blocked blood circulation. DVT has the potential to create a deadly pulmonary embolism (PE) if the blood clot were to separate from the venous wall and become lodged in the patient's lung.
DVT is a very preventable disease even in high risk populations, because the disease is primarily linked to poor or compromised blood flow. Maintaining good blood flow through increasing the velocity of the blood in the peripheral venous network should reduce disease incidents.
VT and PE can be asymptomatic, or may have symptoms like tenderness to the leg or arm in the DVT location, pain, swelling of tissue surrounding the DVT location or discoloration and redness, unexplained shortness of breath, chest pain, anxiety, coughing up blood. DVT incidences range from 200,000 to 600,000 patients per year.
Risk factors for DVT and potential PE include increased age, immobility, obesity, stroke, paralysis, cancer and treatments, major surgery (particularly surgery of the extremities or abdomen), varicose veins, and others.
There are two forms of prophylaxis for DVT prevention. One is drug-based, and the other is device-based.
Pharmalogical anticoagulants impair the normal clotting process within the blood stream of the deep veins. These are successful at preventing clot formation but have drawbacks such as patient drug allergies, medication side effects, increase surgical site bleeding.
Device-based prophylaxis is designed to increase the blood velocity or aid in blood movement through the venous network. Pneumatic compression has been the most studied and appears to be an effective therapeutic technique. These systems are very good at assisting the blood return system in compromised individuals. Draw backs include large and bulky systems that discourage patient mobility and reduce patient compliance. Convention pneumatic compression systems are cumbersome, noisy, and require external power sources, making them suitable only for non-ambulatory patients. Such systems have been associated with poor compliance in trauma patients in a hospital setting, and the poor compliance was associated with a higher rate of DVT.